Job: test or plan a new screen-position relationship rather than repeating blocker work. Ready: approved setup; own broad position descriptions. Say: “What if the screen changes?”
- 0–3: Choose what to investigate about the receiving screen, or propose another distinct question. Check actual source/blocker positions and room arrangements locally.
- 3–8: Offer a short actual look at the existing screen before discussing a model. Identify a useful outcome—shadow height, placement or clarity—without promising an exact ideal result.
- 8–12: Make a prediction and agree to retain source/blocker size/orientation/position for this comparison. Name the screen change and what would be observed. Use an own description/model; the held D before/after facts are not practice data.
- 12–20: Optionally try/repeat the chosen screen comparison. The learner can decide, observe, use an approved instrument or direct an adult. Record if source/blocker also moved or edges changed. The result may be inconclusive; a plan stays a plan if no try occurred.
- 20–25: Compare the available result with the original prediction. Invite a reason to keep/revise or another question, not a demand to agree with the ideal drawing. Keep this new-variable evidence distinct from earlier blocker evidence.